The 'elated' 17-year-old beat off competition from three other finalists - Zoe Plummer, Tim Ankers and Kirsty Cleaver.

The last task on the BBC1 show saw the teens create and market a brand of bottled water.

Quids in: Arjun Rajyagor was crowned the first winner of the Junior Apprentice last night and will get £25,000 to launch his business career

Seal of approval: Lord Sugar congratulated all the finalists for their impressive performances over the weeks

Lord Sugar heaped praise on Arjun, from Essex, declaring: 'Arjun has that natural business flair combined with intelligence that some people are born with - you can't learn it.

'I know that Arjun is going to become the best at whatever he wants to do and I will be here for support all the way.'

Arjun has received a conditional offer to study Engineering Science at Oxford University and aspires to become his own boss of an electrical engineering company.

Close but no cigar: He was in the same team as Tim Ankers, who came runner up, while Kirsty Cleaver was in the losing team

High hopes: Kirsty teamed up with Zoe Plumber, pictured, and the two teams were tasked with creating and marketing a brand of bottled water

He described his win as 'mind-blowing' and his time on the show as 'the most amazing experience of my life'.

The £25,000 prize will be controlled by Lord Sugar and will be carefully handed out when brainbox Arjun wants to take on a suitable venture.

Lord Sugar added: 'I was so impressed with all of the candidates - they were outstanding for their age - but there had to be just one winner, and Arjun has done himself and his family proud.'

Fine tuning: Team Revolution talk through ideas for their advert with a musician

Decisions, decisions: The other teams members think about what kind of bottle they want to use

The final saw Kirsty paired up with Zoe and they opted for the
teenage market, while Tim and Arjun decided to target twentysomething
professionals.

Fired candidates also made a return to help the
hopefuls.

The girls agreed to call their water Drip Drop while the boys opted
for a simple product called A Bottle of Water.

In the
nail-biting final boardroom scene, Lord Sugar showed just how blown away
with their efforts he was as he told the candidates: 'The presentations
that both teams put on were absolutely incredible. You are an
inspiration.'

Choose us: Zoe and Kirsty pitch their product, which they decided to call Drip Drop, to a team of industry people

But he told Zoe and Kirsty that he thought their TV advert 'looked
like a mugging on a council estate'.

He told Tim and Arjun:
'The bottle of water was very simple, very defined and quite clearly I
understood the concept.

'The marketing idea didn't quite come
off that well, the pitch wasn't that great but the professionals were
very, very, very impressed.'

Question and answer session: The girls defend their marketing campaign

Team Revolution: Kirsty
and Zoe were joined by the other sacked contestants

Lord Sugar told the two girls their business model was flawed - but
theirs was a 'hard loss' because he had been so impressed by them.

He
told remaining candidates Tim and Arjun: 'It's a tough choice. And I'm
not going to worry about the runner-up, because I know that the
runner-up is going to succeed anyway.'

Arjun is completing his
A-Levels while continuing to run his computer repair business from
home.

On location: Arjun, left, in a London park filming ad for his team's bottle of water

Pitch time: Arjun and Tim called their product simply A Bottle Of Water, taking questions here from industry people

He is studying for A-Levels in Physics, Maths and Systems &
Control, and AS-Level Further Maths.

He said 'It's been an
amazing opportunity and I can't believe I'm the first Junior Apprentice.

'It's
absolutely mind-blowing and it hasn't even set in yet.

'Tim
was the greatest opponent anybody could have ever wanted.

Waiting to be impressed: Lord Sugar arrives to the boys' pitch night

'My parents are so ecstatic and I hope I've done them proud.

'To
think of the amount of opportunities this will open up for me is just
amazing.'

He added: 'Never in my wildest dreams did I believe
that I would win when I first sent off that application form but now
that I have, I couldn't be more elated.'

Team Instinct: Arjun and Tim were helped by some of the old contestants in the water task

Arjun said of the cash: 'The fund would be fundamental to starting my own business after university, when I will also have the remaining qualifications that I require.

'The business will primarily focus on working at the forefront of new and upcoming technologies... I aspire to, one day, trade with the likes of Nasa and Apple.'